Organic EL device and organic EL panel

Abstract

A transparent electrically conductive film comprising one of In 2 O 3 —ZnO, In 2 O 3 —SnO 2 , ZnO, and SnO 2 is provided on a surface of a metal electrode of an organic EL (electroluminescent) device on the light-emitting layer side, and the thickness of this transparent electrically conductive film is set such as to satisfy the following equation, where L is the optical distance from the organic light-emitting layer to the metal electrode, and λ is the emission wavelength, whereby light reflected by the metal electrode is made to undergo interference and thus strengthen itself in the device; as a result, there are provided an organic EL device and an organic EL panel using the same, according to which the external quantum efficiency can be improved with no accompanying deterioration in the brightness, and moreover the contrast can be improved: L =(2 n +1)λ/4 ( n =0,1,2, . . . ).

The invention claimed is: 
     
       1. An organic electroluminescent devices, comprising:
 a metal electrode; 
 a transparent electrode; 
 an organic electroluminescent light-emitting layer between the metal electrode and the transparent electrode; 
 a transparent electrically conductive film on a surface of the metal electrode, on the organic electroluminescent light-emitting layer side thereof, 
 first means, disposed between the organic electroluminescent light-emitting layer and the transparent electrically conductive film, for injecting first carriers and transporting the first carriers to the organic electroluminescent light-emitting layer, the first means comprising at least one layer of material; 
 second means, disposed between the organic electroluminescent light-emitting layer and the transparent electrode, for injecting second carriers and transporting the second carriers to the organic electroluminescent light-emitting layer, the first means comprising at least one further layer of material, 
 wherein the first carriers are one of holes and electrons and the second carriers are the other of holes and electrons; and 
 wherein the transparent electrically conductive film has a thickness that is set so as to satisfy the following equation, where L is the optical distance from the organic light-emitting layer to the metal electrode, and λ is the wavelength of light emitted by the organic light-emitting layer:
     L =(2 n+ 1)λ/4 ( n= 0,1,2, . . . ).
 
 
 
     
     
       2. The organic electroluminescent device according to  claim 1 , wherein a material of the transparent electrically conductive film is one of In 2 O 3 —ZnO, In 2 O 3 —SnO 2 , ZnO and SnO 2 . 
     
     
       3. A monochrome panel or area color panel, including the organic electroluminescent device according to  claim 1 . 
     
     
       4. The organic electroluminescent device according to  claim 1 , wherein a material of the transparent electrically conductive film is one of In 2 O 3 —ZnO and In 2 O 3 —SnO 2 . 
     
     
       5. An organic electroluminescent devices, comprising:
 a metal electrode; 
 a transparent electrode; 
 an organic electroluminescent light-emitting layer between the metal electrode and the transparent electrode; 
 a transparent electrically conductive film on a surface of the metal electrode, on the organic electroluminescent light-emitting layer side thereof, 
 wherein light of wavelengths different than the wavelength of light emitted by the organic light-emitting layer is absorbed by at least one of the metal electrode and the transparent electrically conductive film, and only light of the wavelength emitted by the organic electroluminescent light-emitting layer is discharged from the transparent electrode, and 
 wherein the organic electroluminescent light-emitting layer emits blue light, the transparent electrically conductive film is constituted from a material of one of In 2 O 3 —ZnO, In 2 O 3 —SnO 2 , ZnO and SnO 2 , containing an impurity of one of CuO, Co and Ti at a concentration of not more than 1%, and the transparent electrically conductive film absorbs light other than blue light. 
 
     
     
       6. The organic electroluminescent device according to  claim 5 , wherein a material of the transparent electrically conductive film is one of In 2 O 3 —ZnO and In 2 O 3 —SnO 2 . 
     
     
       7. A monochrome panel or area color panel, including the organic electroluminescent device according to  claim 5 . 
     
     
       8. The organic electroluminescent device according to  claim 5 , wherein the organic electroluminescent light-emitting layer emits blue light, the metal electrode comprises Zn, Mo or Cr, or an alloy thereof; and the metal electrode absorbs light other than blue light. 
     
     
       9. The organic electroluminescent device according to  claim 5 , wherein the transparent electrically conductive film has an impurity added thereto so as to be colored to a color the same as the color of the light emitted by the organic electroluminescent light-emitting layer. 
     
     
       10. A color conversion type color panel, comprising the organic electroluminescent device according to  claim 5 , a blue monochrome backlight, and color-converting filters, wherein light other than blue light is absorbed by the transparent electrically conductive film of the organic electroluminescent device, and only blue monochrome light from the backlight is reflected by the metal electrode. 
     
     
       11. A color conversion type color panel, comprising:
 an organic electroluminescent device comprising
 a metal electrode, 
 a transparent electrode, 
 an organic electroluminescent light-emitting layer between the metal electrode and the transparent electrode, 
 a transparent electrically conductive film that is provided on a surface of the metal electrode, on the organic electroluminescent light-emitting layer side thereof, 
 first means, disposed between the organic electroluminescent light-emitting layer and the transparent electrically conductive film, for injecting first carriers and transporting the first carriers to the organic electroluminescent light-emitting layer, the first means comprising at least one layer of material, and 
 second means, disposed between the organic electroluminescent light-emitting layer and the transparent electrode, for injecting second carriers and transporting the second carriers to the organic electroluminescent light-emitting layer, the first means comprising at least one further layer of material; 
 
 a blue monochrome backlight; and 
 color-converting filters, 
 wherein the first carriers are one of holes and electrons and the second carriers are the other of holes and electrons; 
 wherein light of wavelengths different than the wavelength of light emitted by the organic light-emitting layer is absorbed by at least one of the metal electrode and the transparent electrically conductive film, and only light of the wavelength emitted by the organic electroluminescent light emitting layer is discharged from the transparent electrode; and 
 wherein light other than blue light is absorbed by the metal electrode, and only blue monochrome light from the backlight is reflected by the metal electrode. 
 
     
     
       12. An organic electroluminescent devices comprising;
 a metal electrode; 
 a transparent electrode; 
 an organic electroluminescent light-emitting layer between the metal electrode and the transparent electrode; 
 a transparent electrically conductive film on a surface of the metal electrode, on the organic electroluminescent light-emitting layer side thereof, 
 first means, disposed between the organic electroluminescent light-emitting layer and the transparent electrically conductive film, for injecting first carriers and transporting the first carriers to the organic electroluminescent light-emitting layer, the first means comprising at least one layer of material; 
 second means, disposed between the organic electroluminescent light-emitting layer and the transparent electrode, for injecting second carriers and transporting the second carriers to the organic electroluminescent light-emitting layer, the first means comprising at least one further layer of material, 
 wherein the first carriers are one of holes and electrons and the second carriers are the other of holes and electrons; 
 wherein the transparent electrically conductive film has a thickness that is set so as to satisfy the following equation, where L is the optical distance from the organic light-emitting layer to the metal electrode, and λ is the wavelength of light emitted by the organic light-emitting layer:
     L =(2 n+ 1)λ/4 ( n= 0,1,2, . . . ); and
 
 
 wherein light of wavelengths different than the wavelength of light emitted by the organic electroluminescent light-emitting layer is absorbed by at least one of the metal electrode and the transparent electrically conductive film, and only light of the wavelength emitted by the organic electroluminescent light-emitting layer is discharged from the transparent electrode. 
 
     
     
       13. The organic electroluminescent device according to  claim 12 , wherein a material of the transparent electrically conductive film is one of In 2 O 3 —ZnO, In 2 O 3 —SnO 2 , ZnO and SnO 2 . 
     
     
       14. A monochrome panel or area color panel, including the organic electroluminescent device according to  claim 12 . 
     
     
       15. The organic electroluminescent device according to  claim 12 , wherein the organic electroluminescent light-emitting layer emits blue light, the metal electrode comprises Zn, Mo or Cr, or an alloy thereof, and the metal electrode absorbs light other than blue light. 
     
     
       16. A color conversion type color panel, comprising the organic electroluminescent device according to  claim 15 , a blue monochrome backlight, and color-converting filters, wherein light other than blue light is absorbed by the metal electrode, and only blue monochrome light from the backlight is reflected by the metal electrode. 
     
     
       17. The organic electroluminescent device according to  claim 12 , wherein the transparent electrically conductive film has an impurity added thereto so as to be colored to a color the same as the color of the light emitted by the organic electroluminescent light-emitting layer. 
     
     
       18. An organic electroluminescent device, comprising
 a metal electrode; 
 a transparent electrode; 
 an organic electroluminescent light-emitting layer between the metal electrode and the transparent electrode; and 
 a transparent electrically conductive film on a surface of the metal electrode, on the organic electroluminescent light-emitting layer side; 
 wherein the transparent electrically conductive film has a thickness that is set so as to satisfy the following equation, where L is the optical distance from the organic light-emitting layer to the metal electrode, and λ is the wavelength of light emitted by the organic light-emitting layer:
     L =(2 n +1)λ/4 ( n =0,1,2, . . .);
 
 
 wherein light of wavelengths different than the wavelength of light emitted by the organic electroluminescent light-emitting layer is absorbed by at least one of the metal electrode and the transparent electrically conductive film, and only light of the wavelength emitted by the organic electroluminescent light-emitting layer is discharged from the transparent electrode; 
 wherein the transparent electrically conductive film has an impurity added thereto so as to be colored to a color the same as the color of the light emitted by the organic electroluminescent light-emitting layer; and 
 wherein the organic electroluminescent light-emitting layer emits blue light, the transparent electrically conductive film is constituted from a material of one of In 2 O 3 —ZnO, In 2 O 3 —SnO 2 , ZnO and SnO 2 , containing an impurity of one of CuO, Co and Ti at a concentration of not more than 1%, and the transparent electrically conductive film absorbs light other than blue light. 
 
     
     
       19. A color conversion type color panel, comprising the organic electroluminescent device according to  claim 18 , a blue monochrome backlight, and color-converting filters, wherein light other than blue light is absorbed by the transparent electrically conductive film of the organic electroluminescent device, and only blue monochrome light from the backlight is reflected by the metal electrode.